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Discussion Starter · #1 ·
Hi guys, back again after tearing down the engine down completely, replaced cam chain, head checked and skimmed slightly, built everything back up being super careful. Torqued everything up to spec. Started bike and there's oil leaking out the head gasket again. I'm at a loss and don't know what to check for next. Anyone had silimar issues/or have any suggestions as to what could be the issue? To say I am pissed off is an understatement.

So it's engine out AGAIN, wtf do I check for next? Thanks hoots
 

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We all know the feeling at one time or another... are you certain it's coming from the head gasket? Could it be coming from one of the cam bearing caps and running down the head fins? It's easy to get one of the cam bearing cap gaskets on backwards on the 350 engine and it will leak oil right away
 

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+1 on the cam bearing gaskets as AD said. Also, the eccentric pins (adjusters) that the rocker arms pivot on, have small o-rings that sit on the ends that slide through the cam bearing caps. If these are deteriorated or not present, you will get a leak in that same area, which can run down the fins and appear to be leaking from somewhere else. I went ahead and replaced all 4 o-rings when I re-postitioned my cam bearing gaskets recently, made all the difference. Unfortunately, I too, have a bit of oil seeping past my head gasket at this point.

I had my engine rebuilt by a local shop about a year ago, I supplied all the new top end components and pistons, as well as a complete gasket and oil seal kit. But the guy who did the rebuild is unfortunately no longer with us... (Car wreck about 2 weeks after I picked up my engine) So I don't even have anyone to ask questions about the build or anything he might have noticed like nicks or gouging in gasket surfaces etc.

Oh well, it's going to get pulled at the end of this riding season once more I guess. Gives me an excuse to do more polishing on the engine and cleaning up harder to reach places on the frame!

Sent from my SAMSUNG-SGH-I537 using Tapatalk
 

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Post some photos. You sure you got all the dowel pins in place?
Can you tell if it's front or back, inside or outside?
Maybe something along the area where the oil gets pumped up?
Photos of everything would be best if you want an extra set of eyes
Are you using the corrcrt head gasket?
 

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Discussion Starter · #5 ·
I thought it was cam cover cap (tachometer) side, order spare fro. Canada as I couldn't get one in U.K.

All eccentric o rings are new, as are gaskets. I am pretty sure it's the head gasket but am really stumped. Checked all round the bottom of the cam cover caps and they are dry.

As engine warms up it drips pretty quick and runs down front of engine and also pools on the cases below underneath the tensioner housing.

I made sure the dome nuts weren't going to top out either. I'm stumped I really am. I could just order another gasket set and redo it all again, but doubt this would achieve anything.
 

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Discussion Starter · #7 ·
Doode, I used an Athena gasket kit. all gaskets in correct order. Oil is getting to top end. It's definitely not the cam caps, just ran again after cleaning and used kitchen roll to confirm. It seems to be from rear of right cylinder at the head gasket (jugs to head interface). I recorded a video but don't know how to put up, or even if I can ?). Thanks
 

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Any chance you put the tach cam cover gasket on backwards?
Rear outer studs is where the oil is pumped. If you put that gasket on backward it'll block the oil flow, but possibly not enough pressure to cause a leak? A photo of your tach side cam cover will confirm.
 

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Discussion Starter · #9 ·
Hi, I don't think so, there's a small hole in that gasket, that I assume needs to line up with cavity in the cap and allow oil to reach the speedo drive ?

Have taken a picture of the old One i replaced, and a couple of the current one installed. Thanks
 

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I torque the head bolts to 17 foot pounds and put oil on the threads as well. This is not the factory spec and using oil is not the factory method.

I follow the factory torque sequence and do it in steps. Might be worth a try.

BTW the torque spec of 17 and oil on the threads was a suggestion from the late Hoyt McClaggen for racing mods and engine rebuilding.
 

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Just a simple FYI the Cam Bearing End Cap gaskets LOOK symetrical but they are NOT.
if installed wrong they will PINCH the o-rings on the ajudters and cause a leak
 

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from the photos it looks backwards. So that's 2 things to check, the gasket orientation and dowel pins between the head and cylinders
 

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I torque the head bolts to 17 foot pounds and put oil on the threads as well. This is not the factory spec and using oil is not the factory method.

I follow the factory torque sequence and do it in steps. Might be worth a try.

BTW the torque spec of 17 and oil on the threads was a suggestion from the late Hoyt McClaggen for racing mods and engine rebuilding.
The science behind this is solid. "Wet torque" (fasteners lubricated with oil/grease) allows you to achieve higher clamping force with less actual torque applied to the fastener itself. This is why many FSM's have separate wet-vs-dry torque figures for certain things.
We used this principle on basically every critical bolt at the high-end bicycle shop I used to work at. Nobody wants the steering head on their $8k Cervélo road bike coming apart while they're pedaling up or downhill pretending to be Lance Armstrong

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Discussion Starter · #14 ·
Hi again, doode, I'll double check gasket, but am I right in thinking the hole on the gasket lines up with the triangle shaped cut out in the cam cap a short per pic of original? As for the dowels, both present and i thought both were same size, so couldn't screw up fitting. It really looks like head isn't seating correctly on the right hand side, so I guess it's pull it out and start again - f me i thought these engines were supposed to be straightforward ?
 

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Discussion Starter · #15 ·
Apologies folks, just to make clear, there is NO leak on the cam caps. I put kitchen paper, wedged in underneath the bottom of both tach and points caps, no oil leak from here. It looks like head gasket which I really don't get, dowels there 100%, is it a ****ty aftermarket head gasket ? Guess there's only one way to find out?
 
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